The Hidden World of Ultrasonic Sound: Using Ultrasonic Microphones in Sound Design
In sound design, capturing details beyond the ordinary spectrum of human hearing opens up new creative possibilities. Ultrasonic microphones, capable of recording frequencies well beyond the typical 20 kHz range, allow sound designers to tap into an unheard world of textures and unique sounds. In this post, we’ll explore how ultrasonic microphones are used in sound design and compare popular options across different budget ranges to help you choose the right one for your projects.
What Is an Ultrasonic Microphone?
An ultrasonic microphone is a specialized type of microphone that records frequencies far beyond what standard microphones can capture, often up to 100 kHz or more. This is especially useful for capturing high-frequency details from animals like bats, insects, or small mechanical sounds that produce ultrasonic tones. The resulting recordings can then be pitched down far greater in post-production to reveal nuanced sounds that bring new dimensions to sound design, often producing eerie, alien, or hyper-realistic textures.
It is important to keep in mind that a recorder capable of recording at a high sample rate of 96k or preferably 192k will be needed to capture ultrasonic frequencies.
How Ultrasonic Microphones Are Used in Sound Design
Capturing Inaudible Textures: Ultrasonic microphones allow sound designers to record sounds that are usually inaudible. These could include high-frequency elements of machinery, the flutter of insect wings, or even ultrasonic emissions from certain materials. When slowed down, these sounds reveal intricate details and textures that enrich a soundscape.
High-Frequency Elements of Machinery: Imagine recording the ultrasonic frequencies produced by a spinning industrial fan. When slowed down, the sound could reveal rhythmic, pulsing tones with subtle metallic resonances, adding depth and realism to a scene set in a factory or sci-fi environment.
Flutter of Insect Wings: By capturing the high-pitched flutter of a dragonfly's wings with an ultrasonic microphone, you could slow down the recording to create a sound reminiscent of small, delicate engines or mechanical drones.
Ultrasonic Emissions from Materials: Certain materials, such as glass or metal, emit faint ultrasonic vibrations when under stress or when rubbed together. When slowed down, these sounds could serve as eerie atmospheres for horror or suspense scenes, adding an unsettling, almost imperceptible layer of tension.
Enhanced Sound Manipulation: By recording sounds at ultrasonic frequencies, designers can slow them down to create exaggerated and surreal effects, perfect for film, game design, or VR applications where exaggerated, hyper-real soundscapes enhance immersion.
Example: In the 2018 God of War video game, the World Serpent, also known as Jörmungandr, is a massive, mythical creature that embodies the ocean and plays a significant role in the game's narrative and atmosphere. To achieve the ancient creature's resonant, otherworldly voice, the sound designer pitch shifted human vocalizations and layeredit with grumbles and rattles of various animal recordings.
Comparing Ultrasonic Microphones Across Budget Ranges
If you’re interested in diving into ultrasonic sound design, choosing the right microphone is essential. Here, we’ll compare three ultrasonic microphones across budget levels: two industry standard options in the Sanken CO-100K (high-end) and Sony ECM-100U (mid-range), and newcomer Sonorous Objects’ SO.104 Ultrasonic Omni Microphone (budget).
1. Sanken CO-100K
Price: High-end, around $2,500
Frequency Range: 20 Hz – 100 kHz
Polar Pattern: Omnidirectional
Connection: XLR
Best for: Professional sound designers, high-end studios, scientific research
Overview: The Sanken CO-100K is the gold standard for ultrasonic recording in sound design. With its ultra-wide frequency range extending up to 100 kHz, it captures high-fidelity ultrasonic sounds with remarkable detail and precision. Built for high-end studios and demanding production environments, the CO-100K is perfect for those needing extreme accuracy and depth, whether recording fine textures or using pitch-shifting techniques to unveil hidden details. Its dual-capsule design allows for a wider, more forgiving polar pattern at extreme high frequencies.
Pros:
Exceptional frequency range (20 Hz – 100 kHz)
High build quality for durability and reliability
Cons:
High cost, suited only for studios or sound designers with large budgets, though you may be able to find one for rent.
2. Sony ECM-100U
Price: Mid-range, around $1,000
Frequency Range: 20 Hz – 50 kHz
Polar Pattern: Cardioid
Connection: XLR
Best for: Intermediate sound designers, mid-range studio setups
Overview: The Sony ECM-100U is an excellent mid-range option for those interested in high-frequency sound capture without the hefty price tag of top-tier models. While its frequency range caps at 50 kHz, it’s still more than sufficient for most ultrasonic applications, capturing detailed audio that can be slowed down and processed effectively. Its cardioid polar pattern makes it ideal for focused recordings.
Pros:
Strong frequency response up to 50 kHz, suitable for ultrasonic recording
Cardioid pattern ideal for isolating sound sources
Cons:
Limited upper frequency extension compared to higher-end models like the Sanken CO-100K. With this microphone or one with a similar frequency response, the recordings will hold up to less pitch shifting (however, if you cannot record at a sample rate above 96kHz to capture those frequencies, it will make little difference).
3. Sonorous Objects SO.104 Ultrasonic Omni Microphone
Price: Budget, around $100
Frequency Range: 10 kHz – 70 kHz
Polar Pattern: Omnidirectional
Connection: XLR
Best for: Entry-level sound designers, experimental setups, smaller studios
Overview: The Sonorous Objects SO.104 Ultrasonic Omni Microphone is a compelling choice for those on a budget, delivering a frequency range that rivals more expensive models. It’s a versatile and affordable option for those new to ultrasonic recording or anyone looking to experiment with ultrasonic capture without a major investment. With its XLR connection, the SO.104 is easy to integrate into professional setups, making it a unique offering at this price point.
Pros:
Impressive frequency range at an affordable price
Compact and portable for on-the-go recording
Cons:
Lower build quality compared to high-end models, which may result in decreased durability and a shorter lifespan, especially in demanding or frequent use, and may point to other inconsistencies in their production. However, the low comparative price may offset these risks.
May lack some off-axis detail offered by more premium options.
Which Microphone Should You Choose?
Cheap plant mic options such as the Zoom H5 are only capable of recording up to 20kHz. The SO.104 look to be a significant upgrade over the handeld’s mics.
For Professional and Scientific Use: The Sanken CO-100K is the best choice for high-end studios and professionals with the budget for top-tier detail and durability. If you're working on scientific research projects, like analyzing animal vocalizations or capturing fine material sounds at ultrasonic frequencies, the CO-100K's extended range makes it invaluable. It’s also ideal for complex sound design projects, as its 100kHz frequency extension allows for twice as much pitch shifting before detail loss compared to mics such as the Sony ECM-100U.
For Versatile Mid-Range Use: The Sony ECM-100U strikes a balance between affordability and quality, offering a solid frequency range and a cardioid polar pattern well-suited for focused recordings. If you're aiming to capture clear, isolated sounds without a high price tag, this microphone is a solid choice– especially for sound designers who need robust ultrasonic capabilities but with recording setups that don't support sample rates above 96 kHz.
For Budget-Conscious and Experimental Use: The Sonorous Objects SO.104 is a compelling choice for those exploring ultrasonic sound on a budget. If you’re new to ultrasonic recording or looking to experiment with capturing high-frequency sounds in less controlled environments, the SO.104 is an affordable, well-specced microphone that still covers an extensive ultrasonic range. Its low price point also makes it ideal for fieldwork or other such risky setups, like placing the mic near unpredictable wildlife or in rugged outdoor environments, where damage to the microphones might be expected and their affordability allows for greater experimentation.
Final Thoughts
Ultrasonic microphones unlock a world of sound that’s otherwise inaccessible, adding depth, texture, and mystery to your sound design projects. From capturing the calls of bats to exploring the rich overtones of mechanical sounds, ultrasonic recording brings an unparalleled range of creative possibilities. Whether you’re investing in a high-end setup with the Sanken CO-100K or experimenting with the Sonorous Objects SO.104, ultrasonic microphones offer unique tools to enhance and expand your creative toolkit.
Encouraged by the given spec data, I recently purchased my own matched stereo pair of Sonorous Objects SO.104. Stay tuned for an upcoming review, where I'll dive deeper into its performance and share insights from my hands-on experience, provide some measurement data, as well as some example recordings. With the right mic in hand, the hidden sounds of the world are yours to capture, manipulate, and transform.
Ready to elevate your project with expert sound design? Let's bring your vision to life! Explore my services or contact me today to discuss your project requirements. Thank you for visiting sameliaaudio.com. Stay tuned for more insights and analysis on cinematic storytelling through sound.